Leucilla echinus

(Haeckel, 1870)

Species Overview

Leucilla echinus (Haeckel, 1870) is a small, spiny, greyish ball-shaped calcareous sponge, with a single oscule. It occurs in deep water, lying unattached on soft bottoms. It is ill-known and recorded only rarely.

Taxonomic Description

Colour: Greyish.
Shape, size, surface and conistency: Small perfectly round balls with spiny surface and single oscule. Size up to 6 mm in diameter, oscule 0.5-1 mm. Consistency fragile.
Spicules: (Leucilla echinus spics) Calcareous. Ectosomal tetractines, with paired rays and basal rays: 400-500 x 50-70 µm, apical rays: 600-800 x 50-70 µm; choanosomal tetractines regular, all rays: 100-200 x 10-12 µm; atrial tetractines sagittal, with paired rays: 400-500 x 50-70 µm, basal rays: 600-800 x 50-70 µm, and apical rays: 400-500 x 50-70 µm; oxeas: 1000-3000 x 60-80 µm.
Skeleton: Leuconoid. Ectosomal skeleton made up of the paired rays of the tetractines; oxeas traverse the whole choanosome and ectosome, and protrude far beyond the surface. Choanosomal skeleton made up of the apical rays of the ectosomal tetractines, the basal rays of the atrial tetractines, and a mass of small choanosomal tetractines. Atrial skeleton made up of the paired rays of the atrial tetractines.
Ecology: Deep water, lying unattached on mud, 92 m.
Distribution: Known only from Norway (Bergen area).
Etymology: Echinus (Latin) = hedgehog or sea-urchin, referring to the spined surface.
Type specimen information: No type material in BMNH.

Remarks

This is an ill-known but apparently distinct calcareous sponge, with no obvious relatives in the area.
Source: Arndt, 1935